Vital Signs: Know What’s Normal for Your HorseBy Kentucky Equine Research Staff · April 10, 2013
When you read a book or magazine article that talks about a horse’s vital signs, the normal rates are almost always given as a range rather than a single number. That’s because an individual equine’s pulse, respiration, temperature, and other signs will be influenced by the horse’s age, stress level, location, health status, fitness, and the time of day, to name a few factors. A young horse taken to its first show or trail ride might have a much faster pulse than an older horse that’s relaxing in its familiar stall at home, and a horse with an infection would probably have a higher temperature and faster breathing rate than one in good health.
When a veterinarian is called to examine your horse for any reason, he will probably check these vital signs and use the results to help determine what may be wrong. You should know the ranges that are normal for your particular horse in order to compare them with whatever the veterinarian has found. To learn about your horse’s vital signs, it will be necessary to take several readings at various times and note any changes you observe.
Checking heart rate is easiest with a stethoscope placed on the girth line just behind the horse’s left elbow. You may have to move the stethoscope around a bit to find the “lub-dub” sound that the heart makes. You can also slide your fingers under the horse’s jaw and feel for the pulse; keep checking by pushing your fingertips outward against the jawbone. The horse’s pulse will rise when you enter the stall, especially if you are carrying tack or are accompanied by a stranger. It will also be higher when the horse is excited or stressed for any reason such as being at an unfamiliar location, in the presence of strange horses, or faced with an unusual stimulus of any kind. The pulse will generally rise with fever, pain, fear, stress, or exertion. It may be lower in horses in top athletic condition and also in horses that are in shock or hypothermia. The normal range is from about 30 to 45 beats per minute for mature horses; foals will have a more rapid pulse.
Counting respiration can be done by watching the ribcage expand and contract, by seeing the horse’s nostrils flare, or by cupping a hand loosely over a nostril and feeling the exhaled breath. The normal range is about 8 to 16 times per minute, generally faster in horses that are nervous or in pain and slower in those in shock, hypothermia, or drug-induced depression. Fit horses also breathe somewhat more slowly; those with colic, discomfort, or heat exhaustion breathe faster, as do horses that have been exercised recently.
Finding the horse’s temperature is probably the simplest chore because a digital thermometer is used for this reading. While someone else is holding the horse, pull the tail out of the way with one hand and slip the lubricated tip of the thermometer about two inches into the horse’s rectum with the other hand. Don’t let go; the thermometer can disappear if the horse tightens its sphincter muscles! When the thermometer beeps or indicates the reading is complete (this make take a minute or two), withdraw the thermometer and check the temperature. The normal range is about 99.5 to 101.5 degrees F, but can be higher in horses with infection, pain, or exposure to strenuous exercise. Horses that have been exposed to high environmental temperatures may also show a rise in body temperature. Lower readings will be seen in horses that are in shock or have hypothermia.
If you have trouble checking your horse’s vital signs, ask your veterinarian to help you learn the proper procedures. You can also find out how to check gum color, dehydration, gut sounds, and the horse’s digital pulse (taken at the fetlock). Knowing the normal readings for your equine will help you and your veterinarian determine what may be wrong with the horse.